Add an OpenCL 1D HistoPyramid algorithm

Ok, this is called an histogram...
But HistoPyramid sounds a bit more expert ;)
Renderer - add support for more texture types and formats
Add the particle grid computation
Remove an unnecessary include
Renderer - fix an include
Remove the hardcoded GRID_SIZE value
First implementation of the simulator, with advection
It will get to one million particles
Add the computation of the total weight

* Add this in the simulator
* Provide methods related to OpenCL on the grid
* Add the file describing the particle structure in the repo
Add basic pressure
Add a loadFile helper function
Move GPU programs in their own files
Move particle.h particle.hpp
Add more constants in the common header
Fix the particles not taking their own weight into account
Add viscosity, and addSpeed kernel and a parametrable gravity
Add the Drawer class
Add a particles class to hold all the state of the particles
Add the main program for the SPH
Add a cursor to show the radius of the interaction